Monthly Archives: February 2015

Understanding Flexible Properties

Epoxy Creep Stress, Flexibility, Strength, Stiffness, & Elongation

by Jeff Wright — Vice President of Technical Services

Above: The notched-beam test for creep stress determines flexible properties.

The Technical Staff at Gougeon Brothers, Inc. regularly discusses material properties in a variety of applications. For example, it is not uncommon for us to discuss with a customer how to use carbon fiber to stiffen a structure, such as the shaft of a kayak paddle, and then within minutes discuss with another how to bond a dimensionally unstable wood, such as oak, and ensure precautions are taken so that the relative movement of the wood will not cause a failure. Continue reading →

Patch Holes in Aluminum Boats with G/flex Epoxy

by Rob Monroe

Above: 12oz fiberglass is used to patch holes in an aluminum boat. Fiberglass patches for both the inside and outside of the hull were wet out with G/Flex 650.

When we started testing G/flex Epoxy as a solution to leaky seams and rivets in aluminum boats, we put out a company-wide call for test boats. John Kennedy offered his old 15′ Michi-Craft canoe, saying he would bring it down from his cabin at the end of hunting season. Not smiling, he asked a few weeks later “just how big a repair we could handle.” It turned out John jack-knifed his utility trailer on an icy road, punching a fist-sized hole in the stern quarter of the canoe. Ouch. Continue reading →

Fix Leaking Rivets in Aluminum Boats with G/flex 650

We have a video demonstrating aluminum boat repair: Fixing Leaking Rivets in an Aluminum Boat.

We wanted to experiment with using G/flex to fix leaking aluminum boats. I was quite surprised to find that every aluminum boat owner I talked to said they had some sort of leak. Within three hours, I had several co-workers volunteer their aluminum boats for the experimental fix using G/flex. Continue reading →

G/flex Shoe Repair

A Step in the Right Direction

by Julie Jezowski

Above: The cracked sole of Julie’s favorite boot prior to this G/flex shoe repair.

My good ol’ faithful boots (meaning they’re old and need to be thrown out but I just can’t do it) blew a deep crack in each sole. I figured what a great time to try out our G/flex Epoxy. Continue reading →

Repairing a Hockey Stick

by Captain James R. Watson

Above: The final step in this hockey stick repair is applying a layer of fiberglass tape to the repair area with G/flex 650 for additional reinforcing.

Ice hockey sticks are exposed to cold temperatures plus high shock forces from contact with the puck as well as with the ice and skates. Hockey sticks can be wood/fiberglass laminates or composites of carbon fiber or aramid. The stick blades often chip and split with use and have to be repaired (or else replaced at $50–$150 each). A customer who repairs and maintains hockey sticks for a local team had been using a conventional epoxy for repairs and found that it often chipped under such use. Continue reading →

Building a Grandson’s Formula 1 Ferrari

By John White of Fife, Scotland

When the first grandson arrives, any grandfather knows he now has the chance to fulfill the dreams he had as a boy. A Formula 1 racing car would do for starters. A small model purchased for £4 was the starting point. The car will be ready for his third birthday so plenty of time (or so I thought). Continue reading →

Tools for Measuring Epoxy Quantities

303 and 305 High-Capacity Positive Displacement Pumps

Above: Measuring epoxy is easier with positive displacement pumps.

For measuring epoxy accurately, Gougeon Brothers, Inc. has introduced high-volume epoxy pumps that are extremely robust. These pumps dispense epoxy faster than any pump the company has previously offered. The 303 and 305 Positive Displacement Pumps work by trapping a fixed amount of resin and hardener, then forcing (displacing) that trapped volume into the discharge pipe or system. The mechanics of this setup mean that increases in resin viscosity due to temperature changes will not slow dispensing speeds. Positive latching lids help prevent contamination of resins and hardeners.

The 305 Metering Pump is an excellent tool for measuring epoxy.

The new 303 Positive Displacement Pump is calibrated for WEST SYSTEM 3:1 ratio epoxies (105 Resin with 207 Special Clear Hardener or 209 Extra Slow Hardener) and is easily identified with a red base. The new 305 Positive Displacement Pump is calibrated for 5:1 ratio epoxies (105 Resin with 205 Fast Hardener or 206 Slow Hardener) and has a blue base.

Positive Displacement Pumps are also available with drum fittings. These connect directly to WEST SYSTEM Resin and Hardener drums so there is no need to decant materials. This setup conveniently streamlines the metering process for high-volume users, saving both time and money.

Several manufacturers offer high-volume pumps that deliver epoxy at upwards of several gallons per minute. Several well-respected pump manufacturers are listed at the end of this article. Their pumps are specially designed to meter epoxy resin and hardener simultaneously at specific ratios. Some of these pumps can meter resin and hardener through a static mixer, so additional mixing isn’t required.

For more information on mixing larqe quantities of epoxy, read Tom Pawlak’s Big Batch Mixing Methods.

Transom Saving Tip

by Tom Pawlak — GBI Technical Advisor

Above: Tom’s transom saving tip is to epoxy conveyor belt material into place, protecting the transom wood from getting crushed by the motor mount screws.

Ten years ago, I replaced the plywood transom in my 16′ aluminum fishing boat. It had gone bad due to the motor mount screw pads crushing the wood from over-tightening, and from shock loads involved in hanging a motor off the back of a boat and traveling down the road at 70 mph. Continue reading →

The RASCAL Project

by Steve Gembrowski

Cover Photo: Steve Gembrowski spent 10 years building the Ken Basset designed RASCAL, a mahogany runabout.

Fifteen years! Not that it took 15 years to build; it was more like a year and a half. I first saw a photograph of RASCAL and decided right then, if I ever build a boat, this is the one. RASCAL was a new design by Ken Basset for a modified V-bottom 14’10” runabout with a beam of 5’4″ and hull weight of 420 pounds. For the next 15 years, RASCAL became one of those projects sitting on the back burner, waiting until I had enough time and money to comfortably build her without having to compromise on engine, equipment or material. I’m sure plenty of builders out there can relate. My first step was to set the standard to which the boat would be built. Continue reading →

A Mile High in Huntsville

Building a competitive model rocket

By Brad Parker

The 2006 NASA Student Launch Initiative (SLI) began for the Flying Tigers, a competitive model rocket club at Caro High School, Michigan, when we accepted the 13th place award in the 2005 Team America Rocketry Challenge at The Plains, Virginia. At that point, we had no idea what we were getting ourselves into. Approximately six months, and thousands of dollars and work hours later, we enjoyed the products of our labor with a perfect flight into the blue Tennessee sky. Continue reading →

Epoxyworks

Building, restoration, and repair with epoxy